The present application claims priority to Italian Patent Application Serial No. MI 2001A 002400, filed Nov. 14, 2001.
The present invention regards a barrel balancing device for break open firearms.
In general, in the field of hand-held firearms and in particular rifles in which the firearm is opened by rotation of the barrel (or barrels) with respect to the breech (or action body), different solutions have been proposed which in some way are intended to balance the barrel or barrels.
Hereafter specific reference shall be made to over-and-under rifles meant for hunting or shooting it being understood that such references can be applied to all collapsible firearms, including side-by-side, semi-automatic, rifled and military ones, etc.
Moreover, given that the invention is directed to experts in the field of firearms, the detailed description of the operation of a rifle has been omitted with regard to the over-and-under rifle which is described. Only the functions of the firearm parts which relate to the technical problem that forms the basis of the invention. Brief mention is made to a common rifle 20, shown in FIG. 1, where its central part is illustrated in the closed position.
In such a figure a barrel or a barrel group 9 is connected to an action body 6 through a hinge pin 7. Such a hinge pin, once the rifle is unlocked through an opening top lever 13, allows the rotation of the barrel group 9 with respect to the action body 6. It is clear that in open position there, the barrel group is in a position such as to allow the expulsion of the cartridge cases and the loading, by the shooter, of new cartridges for subsequent firing.
An iron fore-end 8, is inserted into a fore-end 12, having the function of a grip for the hand of the user, has the function of holding the barrel group 9 locked to the action body 6 and also of allowing dismantling the barrel, once a suitably foreseen fore-end iron catch 11 has been released. Indeed, in the operation of the rifle the iron fore-end acts as a countering rod between a tenon of the barrels 10 and the action body 6. The lock realised by the hinge pin 7 is thus ensured when the barrels are open, preventing the accidental dismantling of the barrels themselves.
Besides this main function, it is known to also provide the iron fore-end with the task of ensuring a sufficient xe2x80x9cpullxe2x80x9d between barrel group and action body, a characteristic realised by forcing the iron fore-end through suitable adjustment of the position of the aforementioned tenon.
This xe2x80x9cpullxe2x80x9d characteristic is desirable since, by realising a countering force in the iron fore-end/action body contact, friction is generated which is capable of creating a state of equilibrium between the open barrels and the action body 6, which would out of balance due to the weight of the barrels.
Thus, at the time of assembly, it is established practice to carry out a manual adjustment on the tenon of the barrels 10 so as to provide a frictional force of the] against the iron fore-end. Such a step which gives the rifle a characteristic xe2x80x9chardxe2x80x9d rotation or a certain resistance of the barrels to movement relative to the action body, does however have drawbacks.
Indeed, by providing a frictional force against the iron fore-end, even when optimal to counter the weight of the barrels, [obliges] the user or shooter, in the barrel loading step, is obliged to apply a substantial additional force in order to overcome the frictional resistances.
Moreover, a small variation of the manual adjustment of the tenon position generates a large variation of the iron fore-end/action body contact force due to the high rigidity of the iron fore-end/action body. Such a variation, besides creating friction, and extremely variable operation from rifle to rifle, can be the cause, in the case of excessive pull of seizures of the iron fore-end/action body contact surfaces.
Finally, given the criticality of the forcing position, a small variation due to normal operating wear, can cause the ideal operating conditions to prematurely deteriorate. In practice, after a few hundred openings/closings, there is a loss of initial pull.
A solution to this technical problem, has been a self-compensating elastic element which is not sensitive to wear. The pull function, usually carried out by the iron fore-end (Franchi patent), is connected to this elastic element. Such an element, in the form of a very powerful spring that is integrated within the iron fore-end, does not, however, solve the problem generated by the friction. Indeed, since small contact forces in the order of between 200 and 300 kg have to be generated in order to realise an acceptable balance, substantial resistance to the iron fore-end/action body rotation is created. Therefore, an object of the present invention is to overcome the limitations of the prior art by attempting to achieve a balanced state which is long-lasting and constant, and which allows easy opening and closing of the firearm by the user.
Another object of the present invention is providing the least possible friction between the iron-fore end and the action body, with small differences between firearms such as rifles.
An object which is fundamental to the previous objects is that of providing low actuation forces and low wear in the moving parts.
Yet another object of the present invention is that of providing good cost-effectiveness in manufacturing and simplicity of assembly.
These and other objects according to the present invention are achieved by providing a barrel balancing device for collapsible firearms as follows:
The barrel balancing device for collapsible firearms (20) has at least one barrel (9) which is mobile for rotation about a fixed hinging point (7) arranged on an action body (6), wherein an open-close top lever (13) is provided between a closed aligned position of said at least one barrel (9) and the action body (6), and a position disengaged and rotated upon opening of said at least one barrel (9) with respect to the action body (6), the at least one barrel (9) is carried by an iron fore-end (8), having at least one elastic or viscoelastic group (21, 22, 23, 24, 25, 26) which interacts between said iron fore-end and said action body to oppose the falling motion of said at least one barrel (9), once said open-close top lever (13) is unlocked, and to realise a balancing push with respect to the weight of said at least one barrel (9) when said collapsible firearm (20) is closed.
The characteristics and advantages of a barrel balancing device for collapsible firearms according to the present invention shall become clearer from the following description, which is given as an example, and not for limiting purposes.